It's a good all around extra project to make some extra income for the shop, or just maybe pick up an idea on making mounts.
It covers a bush method of mounting a second drive pulley to the front of the engine and more professional methods also.
The article also has a simple methods of finding bolt hole centers (where to drill the holes) from tight locations without measuring. Much of the information comes after building over a 100 PTO mounts mostly in the field.
The article was originally written for boats, but the system is the same for most any engine.
The link is-
Hope this helps